A jagged pattern sometimes seen during an attack of migraine.
The act of fortifying; the art or science of fortifying places to strengthen defence against an enemy.
That which fortifies; especially, a work or works erected to defend a place against attack; a fortified place; a fortress; a fort; a castle.
An increase in effectiveness, as by adding ingredients.
A pattern-forming ridge on the surface of a pollen grain.
A wall.